xen-dev-utils

Utility functions used by the Scale Workshop ecosystem.

Installation

npm i

Documentation

Documentation is hosted at the project Github pages.

To generate documentation locally run:

npm run doc

Examples

Test if two arrays are equal:

import {arraysEqual} from 'xen-dev-utils';

const first = [1, 2, 3];
const second = [4, 5];

arraysEqual(first, second);  // false
arraysEqual(second, [4.0, 5.0]);  // true

Mathematically consistent modulo:

mmod(4, 3);  // 1
mmod(-1, 3);  // 2

Calculate convergents of real numbers:

// Convergents are in some sense the best rational approximations of given complexity.
getConvergents(Math.PI);  // ["3/1", "22/7", "333/106", "355/113", ...].map(f => new Fraction(f))
// Each semi-convergents is more accurate than the previous one.
getConvergents(Math.PI, 100, 5, true);  // 3/1, 13/4, 16/5, 19/6, 22/7
// Non-monotonic convergents cover even more ground.
getConvergents(Math.PI, 100, 8, true, true);  // 3/1, 4/1, 7/2, 10/3, 13/4, 16/5, 19/6, 22/7

Clamp values to stay within the specified limits:

clamp(-1, 2, 0.5);  // 0.5
clamp(-1, 2, 2.5);  // 2
clamp(-1, 2, -1.5);  // -1

Convert fractions to their prime components:

// 225/224 = 2**-5 * 3**2 * 5**2 * 7**-1
toMonzo("225/224");  // [ -5, 2, 2, -1 ]

Convert frequencies to cents (comparing to 440Hz).

frequencyToCentOffset(660);  // 701.9550008653874

Convert semitones to natural logarithmic units.

semitonesToNats(5);  // 0.28881132523331055

Get all combinatios of given length

kCombinations([1, 2, 3], 2)  // [[1, 2], [1, 3], [2, 3]]